Rheostat

Description

The inner workings of a rheostat (resistance box). Rheostat contacts (1, 2, 3) are arranged along the outer frame of the body. The contact arm has two contact strips (a, a'), instead of using a regular contact arm. The strips are insulated and press onto contact rings (b, b'). c is a small multiplying resistance, which is equivalent to one of the resistance sections of the rheostat